Apple has released its first “background security improvement” update to fix a security flaw in its Safari web browser across iPhones, iPads, and Macs.
In a security advisory published on Tuesday, the company stated that a researcher identified a vulnerability in WebKit, the core browser engine that powers Safari and several other applications. If exploited, this flaw could allow a malicious website to access data from another site within the same browser session.
Apple described these background security improvements as lightweight updates designed to deliver important security fixes without waiting for full-scale software releases. These updates are automatically pushed to users’ devices in between major system updates.
The feature was introduced for devices running the latest versions of iOS, iPadOS, and macOS (version 26.1 and above). It enables Apple to deploy targeted fixes for specific components such as Safari, the WebKit engine, and other system libraries that may require ongoing security enhancements.
During testing of the new update, installing the background security improvement required only a brief device restart, unlike traditional updates that often involve longer reboot times due to more extensive changes.
Before officially rolling out this first background security improvement, Apple had already distributed several similar fixes to software testers as part of its effort to trial and refine the feature before its public release.
